22 Langford Quality Control

The Laboratory at Langford from its inception was under the direction of a series of eminent Scientists, most of whom participated in research to improve on, and find new methods of treatment and analysis. At least three to my knowledge left Langford to manage laboratories elsewhere. Dr G U Houghton to South Essex Waterworks Co. in Nov 1936, Mr A L Davis joined in 1945, to leave for Hanningfield in 1953, Mr Basil Kekwick to Oxford Water Dept in 1958. Mr John Devall, who was engaged during my period as Laboratory Supervisor at Langford, has attained the prestigious post of Water Director for Northumbrian Water, who own Essex and Suffolk water. As of the 1st May he will be working for Severn Trent Water managig their £6 Billion Investment programme and asset portfolio. When I started work in 1958 it was under Jack(John) Slack, who had started the previous year. He encouraged research into all aspects of the treatment, especially when problems occurred. We were one of the first laboratories to adopt methods for Pesticide and Herbicide analysis, and we succesfully worked for MacDonald and Partners, Consulting Engineers, to develop a method for removal of high silica levels in a major water supply scheme in Riyadh, Saudi Arabia There were also numerous Scientific Papers written for publication, on a wide variety of subjects. A close working relationship was also maintained with Maldon District Council, Environmental Health Dept, David Harper the manager, and Dee Lovell. Complaint samples would be brought in to Langford, rather than taken to the Public Health Laboratory at Chelmsford, which saved MDC and hence the taxpayer the cost of analysis. Additionally, complaints were dealt with quicker for customer satisfaction. Samples were also received from the Marine Swimming Lake, which occasionally had blooms of bright red algae, initiated by the chlorine dosing. The Company also had a statutory duty to supply water below 150 mg/l CaCO3 total hardness.

Langford Laboratory

The Original Laboratory in 1929

Mr A L Davis, Chief Chemist, in Langford Laboratory 1950 He moved to Hanningfield as Chief Chemist in 1953, and sadly died on a train going to a meeting in London

Water treatment is of no use unless there are capable staff who can ensure it is effective and ensures a clean safe drinking water, compliant with regulations.

In the early days, general Laboratory Staff were multi functional, working on Chemical, Microbiological (Bacteriological) and Biological Analysis. Basic Microbiological and Chemical analysis was carried out 7 days a week, to ensure the water quality satisfactory for consumption. As the number of parameters increased, the Laboratory staff then specialised in the respective disciplines mainly of Chemistry and Microbiology.

1948 Analysis Report

When constructed, each water treatment plant had a fully functional laboratory, managed by a Qualified Chemist. During the 1980’s a central laboratory at Hanningfield was implemented with the associated staff reduction from 25 to 12 across the Company. The water quality and purification were controlled on a daily basis, seven days a week, by technical staff at the on site Laboratories under the control of a qualified Chemist and Bacteriologist, as required under the Water Act.

Bacteriology

The methodology used was described as the multiple tube method, glass test tubes containing a sterile growth media McConkey broth and an inverted small tube which had filled with media on sterilisation, and an aluminium cap A known volume of water sample was added to five tubes and incubated at 37 degrees C.

If there were bacteria present the colour changed from red to yellow and gas collected in the small internal tube. Samples were then transferred from these tubes via a 5 millimetre loop of platinum wire that had been flame sterilised in a Bunsen burner, to a series of other tubes containing different media to confirm the type of bacteria present. Flaming the tops of the glass tubes which are held between your fingers, caused hard pads of skin to form which were heat resistant. You can see how evolution works, as if several generations carried out these practices, eventually children would be born with the extra pads of skin. The main indicator bacteria are coliform bacteria which are present in the most numbers in soil and un treated water. E Coli bacteria indicate a sewage pollution.

Pictures below give an indication of relative size of Bacteria and Virus

E Coli Bacteria Virus

The first job of the day is to examine the bacteriological samples, in case there are any positive results, and record the results, and take any action if required. Next, daily samples have to be taken from the treated water reservoir situated between the treatment plant and Ulting Lane, and the raw water entering the plant. The rivers are sampled on a weekly basis. After lunch, samples would be received from the Southend supply area, from all boreholes in supply and underground treated water Reservoirs and Towers, and newly laid mains awaiting approval.

Chemical Analysis

Chemical analysis was carried out for a variety of reasons, the river water was checked to evaluate the level of pollution, the water entering the plant was monitored to establish the amount of chemicals such as lime and soda ash required for softening, and the water leaving the treatment plant was monitored to ensure the quality regulations were met. There was a statutory limit applied to the works for the level of hardness, and if exceeded, there was the risk of a fine for each day. The local authority independently monitored the hardness level. After most of the routine daily analysis had been carried out the periodic monthly analysis was carried out. Regular visits were made to the homes of consumers who had complained about the quality of the supply, with the attendant risks of vicious dogs, and bored housewives. Companies were also visited who were experiencing problems with water based systems or equipment. In summer, approx twenty wells and boreholes sited all over the Southend area were used to augment the supply, these were analysed weekly as the risk of pollution was very low, the samples brought to the Laboratory by the operators who maintained the pumping stations. The depth of these ranged from 150 to over 1000 ft down in the chalk. One borehole on Canvey Island, was suspected of suffering from an intrusion of gas from the nearby underground gas bulk storage facility. As this borehole was pumped continually to waste to protect an adjacent borehole from sea water intrusion it was not deemed a risk.

Most of the work was routine, except when floods occurred and the rivers were then analysed three times a day. In summer there were also numerous visits by coach parties from the distribution area of Rayleigh, and Southend, from schoolchildren to the Women’s Institute. The older visitors were entertained to afternoon tea at the Danbury Tea Rooms after their visit. There was also a seasonal analysis pattern with Summer bringing Algal and Zooplankton ( Daphnia, Cyclops etc) blooms, which blocked the filter beds , and low river levels, caused by insufficient rainfall. Winter brought floods, which resulted in very turbidity or high nitrate levels, requiring a reduction in extraction, the water to be wasted to sea. There was also the annual holly gathering to pick the best, before the gardeners descended to prune the trees. Analysis methods were also constantly under review, with lower concentrations being measured and new parameters also included such as pesticides and herbicides. Apart from the water analysis, other analyses carried out were on the coal for the boilers to test for water content, boiler water to prevent corrosion, sewage samples from the Chelmsford and Witham sewage works that discharged to Beeleigh, and the Langford Sewage works. The European Drinking Water Directive brought fresh challenges, of parameters to be met. We were one of the first companies to adopt Pesticide analysis, attending courses at the Water Research Centre at Medmenham to learn the techniques.

It was a gratifying experience to be part of a team supplying a large population with clean safe drinking water. Intermittent checks were made on Radioactivity levels due to the Bradwell Nuclear Power Station. The cessation of river abstraction has been experienced due to high turbidity or algal levels, cyanide, chemical and oil pollution, and untreated sewage caused by high rainfall. Early annual Laboratory Reports also indicated changes to the original treatment processes brought about by practical observations. Research carried out at Langford in addition to routine quality control, was quite varied and included:- Developing a treatment method for a high silica content water, in Riyadh Corrosion prevention of cast Iron mains Radio Active Isotope Flow tracing through reservoirs Some 13 Scientific papers were published in professional journals, between 1964 and 1985.

Hanningfield Central Laboratory

A range of Analytical equipment in use at Hanningfield

Laboratory Auto Analyzer for simultaneous chemical analysis

Rapid Microbiological Incubator and counterColour Spectrophotometer

Biological Research was carried out at Hanningfield Laboratory predominantly by David Walker our resident Taxidermist, who often had the odd dead creature soaking in a bucket under a bench. This included River and Rainfall surveys for the Sewage Reclamation plant and effects of hormones from sewage on the sex determination of fish.

Distribution System Problems

About the time of the new treatment plant being commissioned into supply, complaints were received from residents of Southend in May 1971 of “worms” being found swimming in their tap water and bath. These were identified as the larval stage of a chironomid, or midge which are commonly seen flying over bodies of water.

Normal chironomid reproductive cycle

Parthenogenetic chironomid reproductive cycle without adult fly stage

These complaints grew in frequency and number reaching a peak in June 1973 of over 557. this resulted in reports in numerous newspapers and even on Television News, both national and local.

Clapperboard, Memento of TV filming in Southend

Following intensive research and with the aid of Biologists from the Natural History Museum, they were discovered to be a species that could breed parthenogenetically, i e without the involvement of a male. The female producing all female fertile eggs.

Top Picture, Head of Chironomid Pupae containing eggs with no form present magnification x 50 (DNW Photos)

Modern Microscope with Camera attachment for photographing such as Chironomid Eggs

Further research indicated that normal levels of chlorination were ineffective controlling them and as a consequence the whole distribution system was dosed with a minute dose of the insecticide Pyrethrins. Similar species are apparently commonly found in the wild, but not in water mains. After publication of two papers of my work in the Journal of the Society for Water Treatment and Examination, I received enquiries regarding similar problems as far apart as South Africa and Michigan USA.

My second paper was co authored with Ian Burfield who assisted with Pyrethrins analysis

Both of my published papers won the award for the best paper of the year by an Author under 40 years of age, and attracted a responses from South Africa and America who were experiencing similar problems.

Also as a result of my research I was awarded Chartered Membership of the Institute of Water and Environmental Managers

DezincificationThe softened water from Langford, also created a problem, in that the softened water reacted with hot pressed brass fittings removing the zinc content and rendering the fittings porous, and partially blocking them with crystalline Zinc Carbonate , also increasing the corrosion of the cast iron distribution mains. This was resolved when the statutory Hardness limit was raised from 150 to 300 mg/l as CaCo3

During a cold winter, difficulties were experienced with the removal of chalk from the vertical flow softening tanks, the chalk sludge appearing more granular and dense. Upon examination, it was discovered that a form of chalk or Calcium Carbonate was being formed that included six molecules of water within its structure. The Shape of the crystals being transformed from their usual raspberry to thin and pencil like. The inclusion of the water within the crystals doubled their weight, and the sharply defined edges were more abrasive to the pumps which had rubber inserts inside an outer casing. Further research showed that the level of phosphate in the water also played a part, the phosphate not being removed by the Aluminium coagulant. Hence the change to Iron Sulphate, which removed the phosphate and cured the problem. This problem had initially been encountered in the Lime Recovery plant, when the chalk was heated in the kiln, the water was released lowering the kiln temperature.

Scientific Papers Published

As a result of various research and observations at Langford , a number of Papers were published over the years, to share the information with the wider Scientific community